Rasberry Pi running 2x Dongles

Need help installing or figuring out something about your SDR? Ask here.
Post Reply
skipro
Posts: 1
Joined: Sat Oct 12, 2019 1:00 am

Rasberry Pi running 2x Dongles

Post by skipro » Sat Oct 12, 2019 1:09 am

Ive been trying to get 2 USB dongles to work together, When I run them separatly they work fine but when I try to run both together in 2 separate terminals the first one stops working and the 2nd doesn't work at all.

The following is the terminal output for running 1 only:

Code: Select all

rtl_fm -f 148.982M -s 22050 -d 0 | multimon-ng -t raw -a POCSAG512 -e -f alpha /dev/stdin >FRNSWpager.txt | sudo python3 /home/pi/FRNSW.py
multimon-ng 1.1.7
  (C) 1996/1997 by Tom Sailer HB9JNX/AE4WA
  (C) 2012-2019 by Elias Oenal
Available demodulators: POCSAG512 POCSAG1200 POCSAG2400 FLEX EAS UFSK1200 CLIPFSK FMSFSK AFSK1200 AFSK2400 AFSK2400_2 AFSK2400_3 HAPN4800 FSK9600 DTMF ZVEI1 ZVEI2 ZVEI3 DZVEI PZVEI EEA EIA CCIR MORSE_CW DUMPCSV X10 SCOPE
Found 2 device(s):
  0:  Realtek, RTL2838UHIDIR, SN: 00000001
  1:  Realtek, RTL2838UHIDIR, SN: 00000001

Using device 0: Generic RTL2832U OEM
Found Rafael Micro R820T tuner
Tuner gain set to automatic.
Tuned to 149235575 Hz.
Oversampling input by: 46x.
Oversampling output by: 1x.
Buffer size: 8.08ms
Exact sample rate is: 1014300.020041 Hz
Allocating 15 zero-copy buffers
Sampling at 1014300 S/s.
Output at 22050 Hz.
POCSAG to Email Converter V1.1


Decoding POCSAG signals...

When I try to run the second one in terminal I get this and no output from both:

Code: Select all

[email protected]:~ $ rtl_fm -f 148.582M -s 22050 -d 1 | multimon-ng -t raw -a POCSAG512 -e -f alpha /dev/stdin >xyzpager.txt | sudo python3 /home/pi/xyz.py
multimon-ng 1.1.7
  (C) 1996/1997 by Tom Sailer HB9JNX/AE4WA
  (C) 2012-2019 by Elias Oenal
Available demodulators: POCSAG512 POCSAG1200 POCSAG2400 FLEX EAS UFSK1200 CLIPFSK FMSFSK AFSK1200 AFSK2400 AFSK2400_2 AFSK2400_3 HAPN4800 FSK9600 DTMF ZVEI1 ZVEI2 ZVEI3 DZVEI PZVEI EEA EIA CCIR MORSE_CW DUMPCSV X10 SCOPE
Found 2 device(s):
  0:  Realtek, RTL2838UHIDIR, SN: 00000001
  1:  Realtek, RTL2838UHIDIR, SN: 00000001

Using device 1: Generic RTL2832U OEM
Found Rafael Micro R820T tuner
POCSAG to Email Converter V1.1


Decoding POCSAG signals...
Tuner gain set to automatic.
Tuned to 148835575 Hz.
Oversampling input by: 46x.
Oversampling output by: 1x.
Buffer size: 8.08ms
Exact sample rate is: 1014300.020041 Hz
Allocating 15 zero-copy buffers
Failed to allocate zero-copy buffer for transfer 8
Falling back to buffers in userspace
Sampling at 1014300 S/s.
Output at 22050 Hz.
I can't bring either online again until after I have rebooted.

Also does anyone know what the command for a graphed output is (I used to use it to check squelch levels)? I have done it previously but can't remember or find it anywhere.

Username
Posts: 505
Joined: Sun Oct 09, 2016 7:27 am

Re: Rasberry Pi running 2x Dongles

Post by Username » Sat Oct 12, 2019 7:45 am

Hi
Thats why I use an Win Server there I could use multiple Sticks at the same Time.

rtlsdrblog
Site Admin
Posts: 2428
Joined: Mon Nov 19, 2012 11:54 pm

Re: Rasberry Pi running 2x Dongles

Post by rtlsdrblog » Thu Oct 17, 2019 8:59 am

Looks like both dongles are running fine.

Not too sure about this, but is /dev/stdin shared? Are you writing two datastreams to the same stdin which is causing the data to get garbled?

Post Reply